cec_read() is non-atomic in the presence of other I2C bus transactions
to the same device.  This presents a problem when we add support for
the TDA9950 CEC engine part - both drivers can be trying to access the
device.

Avoid the inherent problems by switching to i2c_transfer() instead,
which allows us to perform more than one bus transaction atomically.

As this means we will be using I2C transactions rather than SMBUS, we
have to check that the host supports I2C functionality.
Tested-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Some TDA998x contain several different I2C devices - there is the HDMI
encoder, and there is a TDA9950 CEC engine.  These two share the same
interrupt signal.

In order to allow a driver for the CEC engine to work, we need to be
able to share the interrupt with the CEC driver, so convert the handler
and registration to allow this to happen.
Tested-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Disabling the pre-filter block of the TDA998x saves 40mW and the colour
conversion block saves 15mW.  As we always disable these two blocks, we
can power these sections of the chip down to save 55mW of unnecessary
power consumption.
Tested-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Rather than storing the DPMS mode (which will always be on or off) use a
boolean to store this instead.
Tested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

tda998x_audio_get_eld() is needlessly complex - the connector associated
with the encoder is always our own priv->connector.  Remove this
complexity, but ensure that there are no races when copying out the ELD.
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Group the TDA998x audio functions together rather than split between
two different locations in the file, keeping like code together.
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Separate out the connector initialisation from the rest of the drivers
initialisation.
Tested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Group the TDA998x connector functions and funcs structures together
before the encoder support, rather than scattered amongst the rest of
the file.  This keeps like code together.
Tested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

The naming of tda998x_encoder_set_config() is a left-over from when
TDA998x was a slave encoder.  Since this is part of the initialisation,
drop the _encoder from the name, and move it near tda998x_bind().
Tested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Correct two references to tda998x_connector_get_modes() which were
incorrectly referring to tda998x_encoder_get_modes().
Tested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Check for audio support by the attached sink by consulting the EDID
prior to enabling audio over the TMDS link.  We must consult the EDID
after calling drm_helper_probe_single_connector_modes(), as this can
use an override EDID, or load a replacement EDID.
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

The CEA 861B specification indicates the situations when we are able to
send each infoframe based on the version of the EDID's CEA extension.
Update the tda998x driver to follow the CEA specification wrt sending
of infoframes.

Since we only support the generation of AVI version 2, this limits us
to CEA extension version 3, so we treat CEA extension version 2 as
CEA 861 (no infoframes, no audio.)
Tested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Avoid a race between programming audio and an in-progress mode set.
A mode set is complex, and disables the ability to send infoframes
to the sink, and is disruptive to audio - we have to mute the audio
FIFO while doing a mode set.

If an attempt is made to start up the audio side, we will undo the
audio FIFO mute before the mode set has completed.

Move the lock so that we prevent audio interfering with an in-progress
mode set.
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Avoid a racy access to the mode clock by storing the current mode clock
during a mode set under the audio mutex.  This allows us to access it
from the audio path in a safe way.
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

As priv->audio_params can now be changed at run time, we need to be more
careful about how we deal with a mode set.  We must take the audio lock
while checking if there's a valid audio configuration.

However, it's slightly worse than that - during mode set, we mute the
audio, and it must not be unmuted until we have finished the mode set.
It is possible that the audio side may start while a mode set is in
progress, so take the audio_mutex lock around the whole mode setting
procedure.
Tested-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

We will need the audio mutex initialised in all cases, so lets move this
to be early, rather than only being initialised for the DT case.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Connectors shouldn't be registered until the rest of the whole device
is set up, so that consistent state is presented to userspace.

As such, remove the calls to drm_connector_register() and
drm_connector_unregister() from tda998x, as these are now handled by
drm_dev_(un)register() itself.

To work with this change, the mali-dp and hdlcd bind and unbind
sequences have to be reordered, to ensure that the componentised
encoder/connector is bound before drm_dev_register() registers all
connectors. Similarly, the device must be unregistered before the
component is unbound.

Altogether, this allows other drivers using tda998x to be
de-midlayered, and to have less racy initialisation of their components.

Splitting this commit into three (one per driver) isn't possible without
intermediate breakage, so it is all squashed together here.
Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Pull ARM fixes from Russell King:
 "Three relatively small fixes for ARM:

   - Roger noticed that dma_max_pfn() was calculating the upper limit
     wrongly, by adding the PFN offset of memory twice.

   - A fix from Robin to correct parsing of MPIDR values when the
     address size is larger than one BE32 unit.

   - A fix from Srinivas to ensure that we do not rely on the boot
     loader (or previous Linux kernel) setting the translation table
     base register a certain way in the decompressor, which can lead to
     crashes"

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7
  ARM: 8617/1: dma: fix dma_max_pfn()
  ARM: 8616/1: dt: Respect property size when parsing CPUs

If the bootloader uses the long descriptor format and jumps to
kernel decompressor code, TTBCR may not be in a right state.
Before enabling the MMU, it is required to clear the TTBCR.PD0
field to use TTBR0 for translation table walks.

The commit dbece458 ("ARM: 7501/1: decompressor:
reset ttbcr for VMSA ARMv7 cores") does the reset of TTBCR.N, but
doesn't consider all the bits for the size of TTBCR.N.

Clear TTBCR.PD0 field and reset all the three bits of TTBCR.N to
indicate the use of TTBR0 and the correct base address width.

Fixes: dbece458 ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull x86 fixes from Thomas Gleixner:
 "The last regression fixes for 4.8 final:

   - Two patches addressing the fallout of the CR4 optimizations which
     caused CR4-less machines to fail.

   - Fix the VDSO build on big endian machines

   - Take care of FPU initialization if no CPUID is available otherwise
     task struct size ends up being zero

   - Fix up context tracking in case load_gs_index fails"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Fix context tracking state warning when load_gs_index fails
  x86/boot: Initialize FPU and X86_FEATURE_ALWAYS even if we don't have CPUID
  x86/vdso: Fix building on big endian host
  x86/boot: Fix another __read_cr4() case on 486
  x86/init: Fix cr4_init_shadow() on CR4-less machines

Pull MIPS fixes from Ralf Baechle:
 "Another round of fixes:

   - CM: Fix mips_cm_max_vp_width for non-MT kernels on MT systems
   - CPS: Avoid BUG() when offlining pre-r6 CPUs
   - DEC: Avoid gas warnings due to suspicious instruction scheduling by
     manually expanding assembler macros.
   - FTLB: Fix configuration by moving confiuguratoin after probing
   - FTLB: clear execution hazard after changing FTLB enable
   - Highmem: Fix detection of unsupported highmem with cache aliases
   - I6400: Don't touch FTLBP chicken bits
   - microMIPS: Fix BUILD_ROLLBACK_PROLOGUE
   - Malta: Fix IOCU disable switch read for MIPS64
   - Octeon: Fix probing of devices attached to GPIO lines
   - uprobes: Misc small fixes"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: CM: Fix mips_cm_max_vp_width for non-MT kernels on MT systems
  MIPS: Fix detection of unsupported highmem with cache aliases
  MIPS: Malta: Fix IOCU disable switch read for MIPS64
  MIPS: Fix BUILD_ROLLBACK_PROLOGUE for microMIPS
  MIPS: clear execution hazard after changing FTLB enable
  MIPS: Configure FTLB after probing TLB sizes from config4
  MIPS: Stop setting I6400 FTLBP
  MIPS: DEC: Avoid la pseudo-instruction in delay slots
  MIPS: Octeon: mark GPIO controller node not populated after IRQ init.
  MIPS: uprobes: fix use of uninitialised variable
  MIPS: uprobes: remove incorrect set_orig_insn
  MIPS: fix uretprobe implementation
  MIPS: smp-cps: Avoid BUG() when offlining pre-r6 CPUs

Pull sparc fixes from David Miller:

 1) Fix section mismatches in some builds, from Paul Gortmaker.

 2) Need to count huge zero page mappings when doing TSB sizing, from
    Mike Kravetz.

 3) Fix handing of cpu_possible_mask when nr_cpus module option is
    specified, from Atish Patra.

 4) Don't allocate irq stacks until nr_irqs has been processed, also
    from Atish Patra.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix non-SMP build.
  sparc64: Fix irq stack bootmem allocation.
  sparc64: Fix cpu_possible_mask if nr_cpus is set
  sparc64 mm: Fix more TSB sizing issues
  sparc64: fix section mismatch in find_numa_latencies_for_group

Pull networking fixes from David Miller:

 1) Fix wrong TCP checksums on MTU probing when checksum offloading is
    disabled, from Douglas Caetano dos Santos.

 2) Fix qdisc backlog updates in qfq and sfb schedulers, from Cong Wang.

 3) Route lookup flow key protocol value is wrong in ip6gre_xmit_other(),
    fix from Lance Richardson.

 4) Scheduling while atomic in multicast routing code of ipv4 and ipv6,
    fix from Nikolay Aleksandrov.

 5) Fix packet alignment in fec driver, from Eric Nelson.

 6) Fix perf regression in sctp due to struct layout and cache misses,
    from Xin Long.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock
  sctp: change to check peer prsctp_capable when using prsctp polices
  sctp: remove prsctp_param from sctp_chunk
  sctp: move sent_count to the memory hole in sctp_chunk
  tg3: Avoid NULL pointer dereference in tg3_io_error_detected()
  act_ife: Fix false encoding
  act_ife: Fix external mac header on encode
  VSOCK: Don't dec ack backlog twice for rejected connections
  Revert "net: ethernet: bcmgenet: use phydev from struct net_device"
  net: fec: align IP header in hardware
  net: fec: remove QUIRK_HAS_RACC from i.mx27
  net: fec: remove QUIRK_HAS_RACC from i.mx25
  ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route
  ip6_gre: fix flowi6_proto value in ip6gre_xmit_other()
  tcp: fix a compile error in DBGUNDO()
  tcp: fix wrong checksum calculation on MTU probing
  sch_sfb: keep backlog updated with qlen
  sch_qfq: keep backlog updated with qlen
  can: dev: fix deadlock reported after bus-off

When discovering the number of VPEs per core, smp_num_siblings will be
incorrect for kernels built without support for the MIPS MultiThreading
(MT) ASE running on systems which implement said ASE. This leads to
accesses to VPEs in secondary cores being performed incorrectly since
mips_cm_vp_id calculates the wrong ID to write to the local "other"
registers. Fix this by examining the number of VPEs in the core as
reported by the CM.

This patch presumes that the number of VPEs will be the same in each
core of the system. As this path only applies to systems with CM version
2.5 or lower, and this property is true of all such known systems, this
is likely to be fine but is described in a comment for good measure.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14338/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Pull SCSI fix from James Bottomley:
 "One final fix before 4.8.

  There was a memory leak triggered by turning scsi mq off due to the
  fact that we assume on host release that the already running hosts
  weren't mq based because that's the state of the global flag (even
  though they were).

  Fix it by tracking this on a per host host basis"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Avoid that toggling use_blk_mq triggers a memory leak

Pull input fix from Dmitry Torokhov:
 "One small change to make joydev (which is used by older games) to bind
  to devices that export Z axis but not X or Y (such as TRC rudder)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: joydev - recognize devices with Z axis as joysticks

Merge more fixes from Andrew Morton:
 "Three fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/linux/property.h: fix typo/compile error
  ocfs2: fix deadlock on mmapped page in ocfs2_write_begin_nolock()
  mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()

This fixes commit d76eebfa ("include/linux/property.h: fix build
issues with gcc-4.4.4").

With that commit we get the following compile error when using the
PROPERTY_ENTRY_INTEGER_ARRAY macro.

 include/linux/property.h:201:39: error: `u32_data' undeclared (first
                 use in this function)
  PROPERTY_ENTRY_INTEGER_ARRAY(_name_, u32, _val_)
                                       ^
 include/linux/property.h:193:17: note: in definition of macro
                 `PROPERTY_ENTRY_INTEGER_ARRAY'
  { .pointer = { _type_##_data = _val_ } },  \
                 ^

This needs a '.' to reference the union member.  It seems this was just
overlooked here since it is done correctly in similar constructs in
other parts of the original commit.

This fix is in preparation of upcoming commits that will use this macro.

Fixes: commit d76eebfa ("include/linux/property.h: fix build issues with gcc-4.4.4")
Link: http://lkml.kernel.org/r/2de3b929290d88a723ed829a3e3cbd02044714df.1475114627.git.johnyoun@synopsys.comSigned-off-by: John Youn <johnyoun@synopsys.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The testcase "mmaptruncate" of ocfs2-test deadlocks occasionally.

In this testcase, we create a 2*CLUSTER_SIZE file and mmap() on it;
there are 2 process repeatedly performing the following operations
respectively: one is doing memset(mmaped_addr + 2*CLUSTER_SIZE - 1, 'a',
1), while the another is playing ftruncate(fd, 2*CLUSTER_SIZE) and then
ftruncate(fd, CLUSTER_SIZE) again and again.

This is the backtrace when the deadlock happens:

   __wait_on_bit_lock+0x50/0xa0
   __lock_page+0xb7/0xc0
   ocfs2_write_begin_nolock+0x163f/0x1790 [ocfs2]
   ocfs2_page_mkwrite+0x1c7/0x2a0 [ocfs2]
   do_page_mkwrite+0x66/0xc0
   handle_mm_fault+0x685/0x1350
   __do_page_fault+0x1d8/0x4d0
   trace_do_page_fault+0x37/0xf0
   do_async_page_fault+0x19/0x70
   async_page_fault+0x28/0x30

In ocfs2_write_begin_nolock(), we first grab the pages and then allocate
disk space for this write; ocfs2_try_to_free_truncate_log() will be
called if -ENOSPC is returned; if we're lucky to get enough clusters,
which is usually the case, we start over again.

But in ocfs2_free_write_ctxt() the target page isn't unlocked, so we
will deadlock when trying to grab the target page again.

Also, -ENOMEM might be returned in ocfs2_grab_pages_for_write().
Another deadlock will happen in __do_page_mkwrite() if
ocfs2_page_mkwrite() returns non-VM_FAULT_LOCKED, and along with a
locked target page.

These two errors fail on the same path, so fix them by unlocking the
target page manually before ocfs2_free_write_ctxt().

Jan Kara helps me clear out the JBD2 part, and suggest the hint for root
cause.

Changes since v1:
1. Also put ENOMEM error case into consideration.

Link: http://lkml.kernel.org/r/1474173902-32075-1-git-send-email-zren@suse.comSigned-off-by: Eric Ren <zren@suse.com>
Reviewed-by: He Gang <ghe@suse.com>
Acked-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Antonio reports the following crash when using fuse under memory pressure:

  kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: all of them
  CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
  RIP: shadow_lru_isolate+0x181/0x190
  Call Trace:
    __list_lru_walk_one.isra.3+0x8f/0x130
    list_lru_walk_one+0x23/0x30
    scan_shadow_nodes+0x34/0x50
    shrink_slab.part.40+0x1ed/0x3d0
    shrink_zone+0x2ca/0x2e0
    kswapd+0x51e/0x990
    kthread+0xd8/0xf0
    ret_from_fork+0x3f/0x70

which corresponds to the following sanity check in the shadow node
tracking:

  BUG_ON(node->count & RADIX_TREE_COUNT_MASK);

The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.

While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page.  Eventually the page count bits in node->count underflow while
leaving the node incorrectly linked to the shadow node LRU.

To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert().  This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.

Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.

Fixes: 449dd698 ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.orgSigned-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Antonio SJ Musumeci <trapexit@spawn.link>
Debugged-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>	[3.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Change my email address to my kernel.org account instead of the ARM one.
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This warning:

 WARNING: CPU: 0 PID: 3331 at arch/x86/entry/common.c:45 enter_from_user_mode+0x32/0x50
 CPU: 0 PID: 3331 Comm: ldt_gdt_64 Not tainted 4.8.0-rc7+ #13
 Call Trace:
  dump_stack+0x99/0xd0
  __warn+0xd1/0xf0
  warn_slowpath_null+0x1d/0x20
  enter_from_user_mode+0x32/0x50
  error_entry+0x6d/0xc0
  ? general_protection+0x12/0x30
  ? native_load_gs_index+0xd/0x20
  ? do_set_thread_area+0x19c/0x1f0
  SyS_set_thread_area+0x24/0x30
  do_int80_syscall_32+0x7c/0x220
  entry_INT80_compat+0x38/0x50

... can be reproduced by running the GS testcase of the ldt_gdt test unit in
the x86 selftests.

do_int80_syscall_32() will call enter_form_user_mode() to convert context
tracking state from user state to kernel state. The load_gs_index() call
can fail with user gsbase, gsbase will be fixed up and proceed if this
happen.

However, enter_from_user_mode() will be called again in the fixed up path
though it is context tracking kernel state currently.

This patch fixes it by just fixing up gsbase and telling lockdep that IRQs
are off once load_gs_index() failed with user gsbase.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1475197266-3440-1-git-send-email-wanpeng.li@hotmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Otherwise arch_task_struct_size == 0 and we die.  While we're at it,
set X86_FEATURE_ALWAYS, too.
Reported-by: David Saggiorato <david@saggiorato.net>
Tested-by: David Saggiorato <david@saggiorato.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
Link: http://lkml.kernel.org/r/8de723afbf0811071185039f9088733188b606c9.1475103911.git.luto@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

We need to call GET_LE to read hdr->e_type.

Fixes: 57f90c3d ("x86/vdso: Error out if the vDSO isn't a valid DSO")
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: linux-next@vger.kernel.org
Link: http://lkml.kernel.org/r/20160929193442.GA16617@gate.crashing.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

The condition for reading CR4 was wrong: there are some CPUs with
CPUID but not CR4.  Rather than trying to make the condition exact,
use __read_cr4_safe().

Fixes: 18bc7bd5 ("x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly")
Reported-by: david@saggiorato.net
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Link: http://lkml.kernel.org/r/8c453a61c4f44ab6ff43c29780ba04835234d2e5.1475178369.git.luto@kernel.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

When sctp dumps all the ep->assocs, it needs to lock_sock first,
but now it locks sock in rcu_read_lock, and lock_sock may sleep,
which would break rcu_read_lock.

This patch is to get and hold one sock when traversing the list.
After that and get out of rcu_read_lock, lock and dump it. Then
it will traverse the list again to get the next one until all
sctp socks are dumped.

For sctp_diag_dump_one, it fixes this issue by holding asoc and
moving cb() out of rcu_read_lock in sctp_transport_lookup_process.

Fixes: 8f840e47 ("sctp: add the sctp_diag.c file")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Xin Long says:

====================
sctp: a bunch of fixes for prsctp polices

This patchset is to fix 2 issues for prsctp polices:

  1. patch 1 and 2 fix "netperf-Throughput_Mbps -37.2% regression" issue
     when overloading the CPU.

  2. patch 3 fix "prsctp polices should check both sides' prsctp_capable,
     instead of only local side".
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Now before using prsctp polices, sctp uses asoc->prsctp_enable to
check if prsctp is enabled. However asoc->prsctp_enable is set only
means local host support prsctp, sctp should not abandon packet if
peer host doesn't enable prsctp.

So this patch is to use asoc->peer.prsctp_capable to check if prsctp
is enabled on both side, instead of asoc->prsctp_enable, as asoc's
peer.prsctp_capable is set only when local and peer both enable prsctp.

Fixes: a6c2f792 ("sctp: implement prsctp TTL policy")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>